How did they misuse the term symbiotic?
"Symbiosis is a situation in which 2 different organisms live together in close association. Just living in the same place is not enough. By "close association" biologists mean that if they are separated, one (or both!) of these organisms will probably die."
The suit is repairing, or more precisely, filling in human tissue. Shutting down the suit (or removing it) would essentially mean that the user would lose the... whatever that's filling the "holes" and whatnot. The suit's nano shells can be breached. For example, by bullets. In such an event, the suit would fill in the holes, leaving the user dependent on the suit to survive. So hence, the suit and the user are in symbiosis.